1. Field of the Invention
This invention relates to a vertical feed mixer for use in mixing animal feed and, in particular, hay in any form including round bales with other animal feed. In particular, this invention relates to a vertical feed mixer having an auger with a center post and a helical flight extending around said post where the post has an upper surface that is inclined relative to said center axis.
2. Description of the Prior Art
Feed mixers of various forms are known and, in particular, feed mixers for mixing round bales of hay or haylage of any size, including large and small bales with other animal feedstuffs including corn silage, commodities, byproducts and concentrates are known. Previous vertical feed mixers have a vertically mounted auger having a helically-shaped expanding periphery that is narrowest at a top and increases in size towards the base. It is known to have blades mounted periodically along the periphery of the auger. The periphery is smoothly curved in the form of a spiral and expands from top to bottom. These blades are sometimes serrated knives. Alternatively, the auger can have a flight that has a series of straight sections as described in U.S. Pat. No. 5,863,122, issued Jan. 26, 1999. Sometimes, with previous mixers, when a large bale is inserted into the mixer, the bale becomes wedged between a wall of a mixing chamber and the auger with one part of the bale resting on the top of the auger. When a bale is inserted in this position, the bale can remain in that position for a relatively long time before ultimately being broken up by the auger. The time involved obviously varies with the positioning of the bale, but the wrong bale positioning can lead to serious problems. For example, the operator of the mixer might physically attempt to dislodge the blockage and that can be dangerous or unsafe. Also, the efficiency of the mixer is greatly reduced when this type of blockage occurs.